Pro Impact Durahide Speedbag Black - Durable Hanging Swivel Punch Ball for Boxing MMA Muay Thai Fitness or Fighting Sport Training STRONG DURAHIDE MATERIAL. Designed for those who are dedicated to make their mark in the boxing field, the Pro Impact Durahide Speedbag is made using synthetic leather construction for durability to ensure it can hold up to multiple beatings without losing its shape. HIGH-QUALITY CONSTRUCTION. Triple stitched seams are used to ensure the quality and durability of the bag. Additionally, the speedbag comes with a durable rubber bladder and features a lace up for easy bladder removal when needed. GREAT EXERCISE ACTIVITY. Practicing with the Durahide Speedbag is a great cardiovascular exercise which also increases muscle strength and stamina. In addition to burning off calories and keeping you fit, it also helps to tone and sculpt your upper body. MULTIPLE BENEFITS. One is required to make the speedbag move at a constant rate of speed while using consistent punching force. As a result, working out with a speedbag can help to develop your reflexes, increase your speed and improve your hand-eye coordination. CHOICE OF SIZE. To accommodate beginner, intermediate and advanced users, the bag is available in an extra small 5" x 7" size, small bag measuring 6" x 9" and medium 7" x 10" size. Each one is designed to help you build up your hand speed, rhythm and eye contact.